The degeneracy between the wide and close solutions could have been broken if the peak of
the light curve had been covered from followup observations. Due to the high chance of
planetary perturbations near the peaks of light curves, high-magnification events were
important targets for intensive follow-up observations in the microlensing experiments
conducted in a survey+followup mode, in which a survey experiment with a low observational
cadence focused on finding events and followup teams, for example, RoboNet [1]},
MiNDSTEp [2]}, \(\mu \) FUN [3]}, and ROME/REA [4]},
conducted intensive observations for the alerted events. In this mode of lensing experiments,
it was necessary to monitor lensing events found from the survey to select target events for
intensive followup observations. This required prodigious human efforts because it was difficult
to determine which events would have high magnifications based on the sparse data from the surveys.
With the advent of the high-cadence KMTNet survey using globally distributed telescopes, it is
now possible to identify high-magnification events with much less efforts for monitoring, enabling
followup observations that can increase the number of planets found in high-magnification events,
for example, the Earth-mass planet KMT-2020-BLG0414Lb detected from the combined observations by
the KMTNet+MOA surveys and LCO & \(\mu \) FUN Follow-Up Team [5]}. Unfortunately, the
event KMT-2018-BLG-1743 occurred before the operation of the KMTNet AlertFinder system
[6]}, which became fully operational since the 2019 season, and thus a high-magnification
alert could not be issued.
